13- Pre operative Explains Flashcards
What is the mechanism of action of heparin?
Heparin works by causing the formation of complexes between antithrombin and activated thrombin, as well as factors 7, 9, 10, 11, and 12. This inhibits the clotting cascade and prevents the formation of blood clots.
What are the advantages of low molecular weight heparin (LMWH)?
Low molecular weight heparin offers several advantages compared to unfractionated heparin. These include better bioavailability, a lower risk of bleeding, a longer half-life, little effect on the activated partial thromboplastin time (APTT) at prophylactic dosages, and a lower risk of heparin-induced thrombocytopenia (HIT).
What are some complications associated with heparin use?
Complications of heparin use can include bleeding, osteoporosis, heparin-induced thrombocytopenia (HIT) which typically occurs 5-14 days after the first exposure, and anaphylaxis.
What are the specific features of propofol as an IV induction agent?
Propofol has a rapid onset of anesthesia, but it may cause pain upon IV injection. It is rapidly metabolized with minimal accumulation of metabolites. Additionally, propofol has proven antiemetic (anti-nausea) properties and moderate myocardial depression. It is widely used for maintaining sedation in the intensive care unit (ITU), total IV anesthesia, and for daycase surgery.
In surgical patients who may need a rapid return to the operating theater, which type of heparin is preferred?
In surgical patients who may require a rapid return to the operating theater, administration of unfractionated heparin is preferred. This is because low molecular weight heparins have a longer duration of action and are more challenging to reverse if necessary.
What are the specific features of sodium thiopentone as an IV induction agent?
Sodium thiopentone has an extremely rapid onset of action, making it the agent of choice for rapid sequence induction. However, it may cause marked myocardial depression and the buildup of metabolites. It is not suitable for maintenance infusion and has little analgesic effects.
What are the specific features of ketamine as an IV induction agent?
Ketamine may be used for the induction of anesthesia. It has moderate to strong analgesic properties and produces little myocardial depression, making it suitable for anesthesia in individuals who are hemodynamically unstable. However, ketamine may induce a state of dissociative anesthesia, which can result in nightmares.
What are the specific features of etomidate as an IV induction agent?
Etomidate has a favorable cardiac safety profile with minimal hemodynamic instability. It does not possess analgesic properties. However, it is unsuitable for maintaining sedation as prolonged or even brief use may lead to adrenal suppression. Post-operative vomiting is common with the use of etomidate.
What are the possible causes of aortic stenosis?
Aortic stenosis can occur as a result of rheumatic fever, aging, and calcific changes. In congenital cases, it may occur earlier due to the calcification of a bicuspid aortic valve, which affects around 1-2% of the population.
What are the symptoms of aortic stenosis?
Symptoms of aortic stenosis may include exertional angina (chest pain during physical activity) and syncope (fainting).
What is the preferred investigation for diagnosing aortic stenosis?
When aortic stenosis is suspected, trans thoracic echocardiography is the investigation of choice for evaluation and diagnosis.
What are the severity classifications for aortic stenosis based on mean gradient and aortic valve area?
The severity of aortic stenosis can be classified as mild (mean gradient <25 mmHg, aortic valve area >1.5 cm²), moderate (mean gradient 25-40 mmHg, aortic valve area 1.0-1.5 cm²), or severe (mean gradient >40 mmHg, aortic valve area <1 cm²).
What are the treatment options for aortic stenosis?
The treatment for aortic stenosis typically involves either transcatheter or open aortic valve replacement, depending on the individual’s condition and medical evaluation.
What are the recommended preparations for elective surgery?
For elective surgery, it is important to consider a pre-admission clinic to address any medical issues. Blood tests including FBC, U+E, LFT’s, clotting, and Group and Save should be conducted. A urine analysis, pregnancy test, and sickle cell test may also be necessary. Additional tests such as ECG and chest x-ray should be performed based on the proposed procedure and patient fitness. Assessing risk factors for deep vein thrombosis and formulating a plan for thromboprophylaxis is crucial.
How should diabetic patients be prepared for surgery?
Diabetic patients have a higher risk of complications, especially if their diabetes is poorly controlled. Patients with diet or tablet-controlled diabetes may have their medication omitted, with regular blood glucose level checks. Poorly controlled or insulin-dependent diabetics may require an intravenous sliding scale. Potassium supplementation should also be given. Diabetic cases should be prioritized for surgery.
What preparations are necessary for emergency surgery?
For emergency surgery, it is important to stabilize and resuscitate the patient as needed. Antibiotics should be considered if required, and their administration should be determined. If major procedures are planned, particularly when coagulopathies are present or anticipated, the blood bank should be informed. Consent and informing relatives should not be forgotten.
Are there any special preparations for specific procedures?
Yes, some procedures require special preparations. For thyroid surgery, a vocal cord check is necessary. For parathyroid surgery, methylene blue may be considered to identify the gland. Sentinel node biopsy may require a radioactive marker or patent blue dye. Surgery involving the thoracic duct may require the administration of cream. Pheochromocytoma surgery will need alpha and beta blockade. Surgery for carcinoid tumors may require covering with octreotide. Colorectal cases may require bowel preparation, especially for left-sided surgery. Thyrotoxicosis may require Lugol’s iodine or medical therapy.
What are the main stages of wound healing?
The main stages of wound healing include haemostasis, inflammation, regeneration, and remodeling.
What happens during the haemostasis stage of wound healing?
During the haemostasis stage, which occurs minutes to hours following an injury, vasospasm in adjacent vessels, platelet plug formation, and the generation of a fibrin-rich clot take place.
What occurs during the inflammation stage of wound healing?
The inflammation stage typically occurs from day 1 to day 5 after an injury. Neutrophils migrate into the wound, and growth factors such as basic fibroblast growth factor and vascular endothelial growth factor are released. Fibroblasts replicate and migrate into the wound, while macrophages and fibroblasts facilitate matrix regeneration and clot substitution.
What happens during the regeneration stage of wound healing?
The regeneration stage typically occurs from day 7 to day 56. Platelet-derived growth factor and transformation growth factors stimulate the activity of fibroblasts and epithelial cells. Fibroblasts produce a collagen network, angiogenesis occurs, and the wound begins to resemble granulation tissue.
What occurs during the remodeling stage of wound healing?
The remodeling stage takes place from 6 weeks to 1 year after an injury. Fibroblasts become differentiated (myofibroblasts) and aid in wound contraction. Collagen fibers are remodeled, microvessels regress, and a pale scar forms.
What are some factors that can impair the wound healing process?
Conditions such as vascular disease, shock, sepsis, and jaundice can impair microvascular flow and negatively impact wound healing. Additionally, certain drugs like nonsteroidal anti-inflammatory drugs (NSAIDs), steroids, immunosuppressive agents, and anti-neoplastic drugs can impair wound healing.
What are the potential problems with scars?
Hypertrophic scars are characterized by excessive amounts of collagen within the scar. They may contain nodules and can develop contractures. Keloid scars also have excessive collagen, but they extend beyond the boundaries of the original injury and can occur even after trivial injury. Keloid scars do not regress over time and may recur after removal.
What is the difference between delayed primary closure and secondary closure?
Delayed primary closure refers to anatomically precise closure that is delayed for a few days but done before granulation tissue becomes macroscopically visible. Secondary closure can refer to spontaneous closure or surgical closure after granulation tissue has formed.
What are some important principles to appreciate regarding surgical complications?
Some important principles to appreciate regarding surgical complications are the anatomical principles that underpin complications, the physiological and biochemical derangements that occur, the most appropriate diagnostic modalities to utilize, and the principles that underpin their management.
What are some ways to avoid complications in surgery?
Some points to hopefully avert complications in surgery include following the World Health Organisation checklist prior to all operations, using prophylactic antibiotics at the right dose, right drug, and right time, assessing the risk of deep vein thrombosis/pulmonary embolism and ensuring adequate prophylaxis, marking the site of surgery, using tourniquets with caution and respecting underlying structures, avoiding using adrenaline-containing solutions and monopolar diathermy in situations where end arteries are present, handling tissues with care to prevent devitalized tissue as a nidus for infection, and being cautious of potential coupling injuries when using diathermy during laparoscopic surgery.
Why is understanding the anatomy of a surgical field important?
Understanding the anatomy of a surgical field is important because it allows for the appreciation of local and systemic complications that may occur. For example, knowledge of specific nerves in a region can help prevent nerve injuries during surgery.
Can you provide examples of nerves that may be at risk of injury during surgery?
Some examples of nerves that may be at risk of injury during surgery include the accessory nerve during posterior triangle lymph node biopsy, the sciatic nerve during a posterior approach to the hip, the common peroneal nerve when the legs are in the Lloyd Davies position, the long thoracic nerve during axillary node clearance, the pelvic autonomic nerves during pelvic cancer surgery, the recurrent laryngeal nerves during thyroid surgery, and the hypoglossal nerve during carotid endarterectomy.
What are some structures that may be at risk of injury during surgery?
Some structures that may be at risk of injury during surgery include the thoracic duct during thoracic surgery (e.g., pneumonectomy, esophagectomy), the parathyroid glands during difficult thyroid surgery, the ureters during colonic resections or gynecological surgery, the bowel with the use of a Verres Needle to establish pneumoperitoneum, the bile duct with failure to delineate Calot’s triangle carefully and careless use of diathermy, the facial nerve during parotidectomy, the tail of the pancreas when ligating the splenic hilum, the testicular vessels during re-do open hernia surgery, and the hepatic veins during liver mobilization.
What are some physiological and biochemical issues that can lead to complications?
Some physiological and biochemical issues that can lead to complications include susceptibility to hypokalemia (low potassium levels) in cardiac patients following cardiac surgery, neurosurgical electrolyte disturbances such as syndrome of inappropriate antidiuretic hormone secretion (SIADH) causing hyponatremia (low sodium levels) following cranial surgery, ileus (intestinal paralysis) following gastrointestinal surgery resulting in fluid sequestration and loss of electrolytes, pulmonary edema (fluid accumulation in the lungs) following pneumonectomy (surgical removal of a lung) due to loss of lung volume making patients sensitive to fluid overload, anastomotic leak leading to generalized sepsis causing mediastinitis (inflammation of the space between the lungs) or peritonitis (inflammation of the abdominal lining) depending on the site of the leak, and myocardial infarction (heart attack) that may follow any type of surgery and can compromise grafts and decrease cardiac output.
What are some baseline investigations that are often helpful in acutely unwell surgical patients?
Some baseline investigations that are often helpful in acutely unwell surgical patients include a full blood count, urea and electrolytes, C-reactive protein (trend rather than absolute value), serum calcium, liver function tests, clotting (should be repeated if ongoing bleeding is present), arterial blood gases, ECG (electrocardiogram) with cardiac enzymes if myocardial infarction is suspected, chest x-ray to identify collapse or consolidation in the lungs, and urine analysis for urinary tract infection. These investigations can often identify the most common complications.
What are some special tests that can be used to identify specific complications?
Some special tests that can be used to identify specific complications include CT scanning for the identification of intra-abdominal abscesses, Doppler ultrasound of leg veins for the identification of deep vein thrombosis, CTPA (computed tomography pulmonary angiography) for pulmonary embolism, sending peritoneal fluid for urea and electrolyte analysis if ureteric injury is suspected, sending peritoneal fluid for amylase analysis if pancreatic injury is suspected, and echocardiogram if pericardial effusion (fluid around the heart) is suspected post cardiac surgery and no pleural window was made.
What is the guiding principle for managing complications?
The guiding principle for managing complications should be safe and timely intervention. Patients should be stabilized, and if an operation needs to occur alongside resuscitation, it should generally be a damage limitation procedure rather than definitive surgery. Definitive surgery can be more safely undertaken in a stable patient the following day.
What is the recommended approach for laparotomies in cases of bleeding?
As a general rule, laparotomies for bleeding should follow the core principle of quadrant packing and subsequent pack removal rather than plunging large clamps into pools of blood. The latter approach often worsens the situation and can result in significant visceral injury, especially when done by inexperienced individuals. If packing effectively controls the situation, it is entirely acceptable to leave packs in place and return the patient to the intensive care unit (ICU) for pack removal the following day.
What are the indications for IV fluids in children?
The indications for IV fluids in children include resuscitation and circulatory support, replacing ongoing fluid losses, providing maintenance fluids for children who cannot take oral fluids, and correcting electrolyte disturbances.
Which fluids should be avoided in children outside the neonatal period?
In children outside the neonatal period, saline/glucose solutions should be avoided. The greatest risk is associated with saline 0.18%/glucose 4% solutions. The report suggests that 0.45% saline/5% glucose may be used, but preference should be given to isotonic solutions and there are few indications for this solution as well.
Which fluids are recommended for use in paediatric fluid management?
The recommended fluids for paediatric fluid management include 0.9% saline, 5% glucose (but only with saline for maintenance and not to replace losses), and Hartmann’s solution.
What should be considered when adding potassium to maintenance fluids?
Potassium should be added to maintenance fluids based on the patient’s plasma potassium levels, which should be monitored.
What type of fluid should neonates receive during surgery?
Neonates should receive glucose 10% during surgery.
What type of fluid should other children receive during surgery?
Other children should receive isotonic crystalloid during surgery.
What is the recommended rate of glucose administration for neonates?
Neonates usually require glucose 10% at a rate of 60ml per kilogram of body weight per day.
What are the recommended water and electrolyte requirements for maintenance fluids based on the child’s weight?
For maintenance fluids, the water requirement per kilogram of body weight is 100ml for the first 10kg, 50ml for the second 10kg, and 20ml for subsequent kilograms. The sodium requirement per kilogram of body weight is 2-4 mmol for the first 10kg, 1-2 mmol for the second 10kg, and 0.5-1.0 mmol for subsequent kilograms. The potassium requirement per kilogram of body weight is 1.5-2.5 mmol for the first 10kg, 0.5-1.5 mmol for the second 10kg, and 0.2-0.7 mmol for subsequent kilograms.
What is the technique used for splenectomy in cases of trauma?
In cases of trauma, splenectomy is performed under general anesthesia. A long midline incision is made, and if time permits, a self-retaining retractor (e.g., Balfour or omnitract) is inserted. Since there is usually a large amount of free blood present, all four quadrants of the abdomen are packed. The viability of the spleen is assessed after removing the packs, and if there are hilar injuries or extensive parenchymal lacerations, splenectomy is usually required. The short gastric vessels are divided and ligated, followed by clamping and ligating the splenic artery and vein. Care should be taken not to damage the tail of the pancreas, as this may require formal removal and closure of the pancreatic duct. The abdomen is washed out, and a tube drain is placed in the splenic bed. Some surgeons choose to implant a portion of the spleen into the omentum, but this is a personal choice. Postoperatively, the patient will require prophylactic penicillin V and pneumococcal vaccine.
What are the indications for splenectomy?
The indications for splenectomy include trauma (with 1/4 being iatrogenic), spontaneous rupture due to EBV, hypersplenism (associated with conditions like hereditary spherocytosis or elliptocytosis), malignancy (such as lymphoma or leukemia), and conditions like splenic cysts, hydatid cysts, and splenic abscesses.
How is elective splenectomy different from emergency splenectomy?
Elective splenectomy is different from emergency splenectomy in terms of the operation setting and the size of the spleen. Elective splenectomies are often performed laparoscopically and the spleen is usually large, sometimes massive. The spleen is typically macerated inside a specimen bag to facilitate extraction.
What are the complications associated with splenectomy?
Complications of splenectomy include early hemorrhage (which can occur from short gastrics or splenic hilar vessels), pancreatic fistula (resulting from iatrogenic damage to the pancreatic tail), and thrombocytosis (for which prophylactic aspirin may be given). There is also an increased risk of post-splenectomy sepsis, particularly from encapsulated bacteria such as Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis.
What is post-splenectomy sepsis typically associated with?
Post-splenectomy sepsis typically occurs with encapsulated organisms. Opsonization occurs, but these organisms are not recognized effectively by the immune system.
What changes occur in the blood following splenectomy?
Following splenectomy, platelet levels rise first, so in cases of ITP, platelets should be given after clamping the splenic artery. The blood film will also change over the following weeks, with the appearance of Howell-Jolly bodies, target cells, and Pappenheimer bodies. There is an increased risk of post-splenectomy sepsis, so prophylactic antibiotics and pneumococcal vaccine should be administered.
What are the nutrition options available for surgical patients?
The nutrition options for surgical patients include oral intake, nasogastric feeding, nasojejunal feeding, feeding jejunostomy, percutaneous endoscopic gastrostomy, and total parenteral nutrition.
What is the easiest option for nutrition in surgical patients?
Oral intake is the easiest option for nutrition in surgical patients. It may be supplemented by calorie-rich dietary supplements. However, it may be contraindicated following certain procedures.
What is nasogastric feeding and how is it administered?
Nasogastric feeding is usually administered via a fine bore nasogastric feeding tube. Complications of nasogastric feeding include aspiration of feed or misplaced tube. It may be safe to use in patients with impaired swallowing. However, it is often contraindicated following head injury due to the risks associated with tube insertion.
What is nasojejunal feeding and when is it typically used?
Nasojejunal feeding is a nutrition option that avoids problems of feed pooling in the stomach and the risk of aspiration. The insertion of the feeding tube is more technically complicated, and it is easiest if done intraoperatively. Nasojejunal feeding is safe to use following oesophagogastric surgery.
What is feeding jejunostomy and when is it used?
Feeding jejunostomy is a surgically sited feeding tube that may be used for long-term feeding. It has a low risk of aspiration and is thus safe for long-term feeding following upper gastrointestinal surgery. The main risks associated with feeding jejunostomy are tube displacement and peritubal leakage immediately following insertion, which carries a risk of peritonitis.
What is the mechanism of action of warfarin?
Warfarin is an oral anticoagulant that inhibits the reduction of vitamin K to its active hydroquinone form. This, in turn, acts as a cofactor in the formation of clotting factors II, VII, IX, and X, as well as protein C.
What is percutaneous endoscopic gastrostomy (PEG) and what are its risks?
Percutaneous endoscopic gastrostomy (PEG) is a nutrition option that involves combined endoscopic and percutaneous tube insertion. However, it may not be technically possible in patients who cannot undergo successful endoscopy. Risks of PEG include aspiration and leakage at the insertion site.
What is total parenteral nutrition (TPN) and when is it used?
Total parenteral nutrition (TPN) is the definitive option for patients in whom enteral feeding is contraindicated. It requires individualized prescribing and monitoring and should be administered via a central vein as it is strongly phlebitic. Long-term use of TPN is associated with fatty liver and deranged liver function tests (LFTs).
What are some factors that may potentiate the effects of warfarin?
Factors that may potentiate the effects of warfarin include liver disease, P450 enzyme inhibitors such as amiodarone and ciprofloxacin, cranberry juice, drugs that displace warfarin from plasma albumin (e.g., NSAIDs), and drugs that inhibit platelet function (e.g., NSAIDs).
What are the side-effects of warfarin?
The side-effects of warfarin include hemorrhage, teratogenic effects, and skin necrosis. Skin necrosis can occur when warfarin is first started due to reduced biosynthesis of protein C, resulting in a temporary procoagulant state. This is normally avoided by concurrent administration of heparin. Thrombosis may occur in venules, leading to skin necrosis.
What is the World Health Organisation (WHO) Analgesic Ladder?
The World Health Organisation (WHO) Analgesic Ladder is a stepwise approach for the management of pain. It begins with the use of peripherally acting drugs such as paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs). If pain control is not achieved, weak opioid drugs like codeine or dextropropoxyphene are introduced, along with agents to control side effects. The final step is the use of strong opioid drugs like morphine. Peripherally acting drugs and centrally-acting opioids can be given together for additive analgesic effects.
What is the World Federation of Societies of Anaesthesiologists (WFSA) Analgesic Ladder?
The World Federation of Societies of Anaesthesiologists (WFSA) Analgesic Ladder is a similar approach for the management of acute pain. Initially, severe pain may be controlled with strong analgesics in combination with local anesthetic blocks and peripherally acting drugs. The second step involves restoring the use of the oral route for analgesia, using combinations of peripherally acting agents and weak opioids. The final step is when pain can be controlled by peripherally acting agents alone.
What are some methods for providing local anesthesia and pain relief?
Methods for providing local anesthesia and pain relief include infiltration of a wound with a long-acting local anesthetic like bupivacaine, blockade of plexuses or peripheral nerves, spinal anesthesia, epidural anesthesia, transversus abdominal plane block (TAP), and patient-controlled analgesia (PCA).
Strong Opioids, Weak opioids, Paracetamol, NSAIDs
What are the advantages and disadvantages of spinal anesthesia?
Advantages of spinal anesthesia include excellent analgesia for surgery in the lower half of the body and prolonged pain relief after the operation. However, side effects can include hypotension, sensory and motor block, nausea, and urinary retention.
What are the advantages and disadvantages of epidural anesthesia?
Advantages of epidural anesthesia include excellent analgesia and prevention of postoperative respiratory compromise. However, disadvantages include confinement to bed, especially with a motor block, and the need for an indwelling urinary catheter. Epidurals are contraindicated in coagulopathies.
What is a transversus abdominal plane block (TAP)?
A transversus abdominal plane block (TAP) is a technique where an ultrasound is used to identify the correct muscle plane, and local anesthetic (usually bupivacaine) is injected. This blocks many of the spinal nerves and provides a wide field of blockade. TAP is preferred for extensive laparoscopic abdominal procedures as it does not require the placement of indwelling devices and does not cause postoperative motor impairment. However, its duration of action is limited to the half-life of the local anesthetic chosen.
What are the characteristics of pethidine?
Pethidine is a synthetic opioid with similar actions to morphine. It has a short half-life and similar bioavailability and clearance. It has a short duration of action and may need to be given hourly. Pethidine has a toxic metabolite called norpethidine, which can accumulate in renal failure or with frequent and prolonged doses, leading to muscle twitching and convulsions. Extreme caution is advised if pethidine is used over a prolonged period or in patients with renal failure.
What is patient-controlled analgesia (PCA)?
Patient-controlled analgesia (PCA) is a method where patients administer their own intravenous analgesia using a small microprocessor-controlled pump. The dose can be titrated to their own desired level of pain relief. Morphine is commonly used for PCA.
What are the characteristics of morphine?
Morphine has a short half-life and poor bioavailability. It is metabolized in the liver and its clearance is reduced in patients with liver disease, the elderly, and the debilitated. Side effects include nausea, vomiting, constipation, and respiratory depression. Tolerance may occur with repeated dosage.
What are the characteristics of NSAIDs?
NSAIDs have analgesic and anti-inflammatory actions. They work by inhibiting prostaglandin synthesis. All NSAIDs work in the same way, so there is no point in giving more than one at a time. They are more useful for superficial pain arising from the skin, buccal mucosa, joint surfaces, and bone. They have relative contraindications, including a history of peptic ulceration, gastrointestinal bleeding or bleeding diathesis, operations associated with high blood loss, asthma, moderate to severe renal impairment, dehydration, and any history of hypersensitivity to NSAIDs or aspirin.
What are the characteristics of paracetamol?
Paracetamol inhibits prostaglandin synthesis and has analgesic and antipyretic properties. It has little anti-inflammatory effect. It is well absorbed orally and metabolized almost entirely in the liver. It is widely used for the treatment of minor pain but can cause hepatotoxicity in overdose.
What are the first-line medications for neuropathic pain according to the National Institute of Clinical Excellence (UK) guidelines?
The first-line medications for neuropathic pain are amitriptyline (or imipramine if cannot tolerate) or pregabalin.
What are the second-line medications for neuropathic pain according to the National Institute of Clinical Excellence (UK) guidelines?
The second-line medications for neuropathic pain are amitriptyline AND pregabalin.
When should a pain specialist be referred to for neuropathic pain management?
If first and second-line medications are ineffective or if the pain is diabetic neuropathic pain, a pain specialist should be referred to. In the interim, tramadol can be given, but morphine should be avoided.
What medication is recommended for diabetic neuropathic pain?
For diabetic neuropathic pain, duloxetine is recommended.
What is the procedure for transurethral prostatectomy?
Transurethral prostatectomy involves the insertion of a resectoscope via the penile urethra. The bladder and prostate are irrigated, and strips of prostatic tissue are removed using diathermy.
What are the indications for surgery in patients with benign prostatic hyperplasia (BPH)?
The indications for surgery in patients with BPH include refractory urinary retention, recurrent urinary tract infections due to prostatic hypertrophy, recurrent gross hematuria, renal insufficiency secondary to bladder outlet obstruction, permanently damaged or weakened bladders, and large bladder diverticula that do not empty well due to an enlarged prostate.
What are the complications of transurethral prostatectomy?
The complications of transurethral prostatectomy include hemorrhage, urosepsis, retrograde ejaculation, and electrolyte disturbances from the irrigation fluids used during surgery.
What are the risk factors for increased morbidity following transurethral prostatectomy (TURP)?
The risk factors for increased morbidity following TURP are glands larger than 45g, operating time exceeding 90 minutes, and acute urinary retention as the presenting feature.
What are the causes of hyperthyroidism?
The causes of hyperthyroidism include diffuse toxic goiter (Graves Disease), toxic nodular goiter, toxic nodule, and rare causes.
What is Graves disease?
Graves disease is characterized by a diffuse vascular goiter and is most common in younger females. It may be associated with eye signs. Symptoms of hyperthyroidism predominate in this condition.
What is toxic nodular goiter?
Toxic nodular goiter is characterized by the presence of a goiter for a long period of time before the development of clinical symptoms. In some cases, the hyperthyroidism is caused by the internodular tissue rather than the nodules.
What is a toxic nodule?
A toxic nodule is an overactive, autonomously functioning nodule. It may occur as part of generalized nodularity or be a true toxic adenoma. TSH levels are usually low due to the negative feedback effect of the autonomously functioning thyroid tissue.
What are the signs and symptoms of hyperthyroidism?
The signs and symptoms of hyperthyroidism include lethargy, tachycardia, agitation, heat intolerance, weight loss, excessive appetite, palpitations, exophthalmos, hot and moist palms, thyroid goiter and bruit, and lid lag/retraction.
What is the most sensitive test for diagnosing hyperthyroidism?
The most sensitive test for diagnosing hyperthyroidism is plasma T3, which is typically raised.
What is the first-line treatment for Graves disease?
The first-line treatment for Graves disease is usually medical, and the block and replace regime is the favored option. This involves administering higher doses of carbimazole and orally administering thyroxine. Patients are maintained on this regime for 6 to 12 months, and attempts are made to wean off medication.
What are the treatment options for Graves disease if relapse occurs after initial treatment?
If relapse occurs after initial treatment for Graves disease, the options include ongoing medical therapy, radioiodine, or surgery.
What is endoscopy?
Endoscopy is a procedure that allows for the internal visualization of the viscera. It is commonly used for procedures such as gastroscopy, colonoscopy, cystoscopy, ERCP, and bronchoscopy. Unlike laparoscopy, endoscopy does not typically involve the inspection of a visceral cavity.
What are the components of most endoscopes?
Most endoscopes are flexible instruments with three channels and a video chip with an illumination source at the end. The channels are used for suction, irrigation, and instrumentation. The flexible instruments also have a control stack with wheels that allow for manipulation of the instrument’s tip.
What are some considerations for performing endoscopies?
Endoscopies should be performed in dedicated units with appropriately trained staff and full resuscitation facilities available. Some procedures may require patient sedation, while others may not.
What is the preparation for endoscopy?
The preparation for endoscopy depends on the organ to be examined. For ERCP, clotting, antibiotics, and Vitamin K may be necessary if the patient is jaundiced. For diagnostic OGD (esophagogastroduodenoscopy), the patient should be nil by mouth for 6 hours. For flexible sigmoidoscopy, a phosphate enema should be administered 30 minutes before the procedure. For colonoscopy, U+E (urea and electrolyte) levels should be checked, and if normal, oral purgatives such as picolax may be prescribed.
What are the different routes for establishing venous access?
The different routes for establishing venous access include peripheral venous cannula, central lines, intraosseous access, tunneled lines, and peripherally inserted central cannula (PICC) lines.
What are the advantages and disadvantages of peripheral venous cannula?
Peripheral venous cannulae are easy to insert with minimal morbidity and allow for rapid fluid infusions. However, they are unsuitable for administering vasoactive drugs and irritant drugs, such as TPN, except in the very short term setting. Infections at peripheral sites can also occur.
What are the considerations for central lines?
Insertion of central lines is more difficult and often requires the use of ultrasound. Coagulopathies can lead to hemorrhage from iatrogenic arterial injury. While femoral lines are easier to insert, they are prone to high infection rates. The internal jugular route is preferred. Central lines have multiple lumens for administering multiple infusions, but the lumens are relatively narrow, limiting the rate of infusion.
What is intraosseous access?
Intraosseous access involves accessing the marrow cavity and circulatory system through the anteromedial aspect of the proximal tibia. Although traditionally used in pediatric practice, it can also be used in adults. Intraosseous access allows for the infusion of a wide range of fluids.
What are tunneled lines?
Tunneled lines, such as Groshong and Hickman lines, are devices commonly used for patients with long-term therapeutic requirements. They are inserted into the internal jugular vein using ultrasound guidance and then tunneled under the skin. A cuff helps anchor the device into the tissues. These lines can be linked to injection ports located under the skin, which is especially popular in pediatric practice.
What are peripherally inserted central cannula (PICC) lines?
PICC lines are methods for establishing central venous access. They are inserted peripherally, making them less prone to major complications related to device insertion compared to conventional central lines.
What is the risk of untreated deep vein thrombosis in surgical patients?
Untreated deep vein thrombosis in surgical patients can progress and result in pulmonary embolism.
What are the factors that increase the risk of deep vein thrombosis in surgical patients?
The following factors increase the risk of deep vein thrombosis in surgical patients: surgery lasting more than 90 minutes (or more than 60 minutes involving the lower limbs or pelvis), acute admissions with an inflammatory process involving the abdominal cavity, expected significant reduction in mobility, age over 60 years, known malignancy, thrombophilia, previous thrombosis, BMI over 30, taking hormone replacement therapy or the contraceptive pill, varicose veins with phlebitis.
What are some mechanical thromboprophylaxis methods?
Mechanical thromboprophylaxis methods include early ambulation after surgery, compression stockings (contraindicated in peripheral arterial disease), intermittent pneumatic compression devices, and foot impulse devices.
